I ran Tow Trucks for 15 years and knew the boys in blue very well.  The way it was explained to me was  "if you put a load on it, it's a trailer" and "if it is a piece of machinery like a cement mixer or a portable welder (fixed permanent load)" it doesn't.  The laws may have changed but the way they looked at it was a car dolly was a trailer.  When traveling in some US states you need brakes on all 4 wheels so the dolly has brakes and the brake buddy applies the cars rear brakes.  I would plate the dolly so I don't have to stand on the side of the road and argue about it.

-- Edited by RWW on Sunday 22nd of March 2015 09:37:20 PM

I've had several tow dollies, and never plated them. Never got an ownership for them. Surge brakes saved my a$$ a few times though.

when researching "tow dollies" use the words trailer converter dolly HTA MTO....

the "tow dolly" is NOT a trailer.. I had an official email from MTO that stated this, but seem to have lost it..

altho it seems you can call it anything you want......... I have found that the local License office will not give you plates if you ask for trailer convertor dolly, as a plate can not be issued for a converter dolly

if you look at combination semi trailers... you will see a * trailer converter dolly* between the front trailer and the rear trailer.... it "converts" from a pintle hitch,, to a fifth wheel..

the tow dolly used behind a motor home converts from a ball hitch to a fifth wheel...
this is where they get interesting...
if you have a salvage license , you can tow a wreck with one axle on the ground.. usually behind a tow truck
if you don't ,, the vehicle with one axle on the ground must be licensed and insured. this is where the converter is usually hauling a licensed trailer on it... remember,, 2 semi trailers need a converter ,,, the second vehicle is a trailer.

in the case of a motor home,, the second vehicle is a car with one axle on the ground..

so those folks hauling a toad car behind the motorhome have a legal combination of tow vehicle and towed vehicle with an adapter between them.. and usually a small car and the converter is less than 4500kg.. and RV's are exempt

those folks who choose to use that adapter with a plate on it ,, making it a trailer ,,, are effectively hauling a load that has fallen off the back of his trailer ,,,

if it is not behind an RV,, then all the rules can apply

a converter adapter always requires lights, 2 chains,, and sometimes brakes in a situation over a certain weight.

oh,, recently I found that the wreck can be exempt if it is a race car.
I have not researched a "race car" in this situation... other places define a race car as under sanctions by a registered sanctioning body..
It gets complicated.
if it is over the CVOR weights,, then yellow stickers, and daily logs enter in to the picture..

the law states
ONTARIO REGULATION 199/07
COMMERCIAL MOTOR VEHICLE INSPECTIONS
Exemptions
4. (1) Subsections 107 (4) to (12) of the Act and Part II of this Regulation do not apply in respect of the following classes of vehicles, used in the following circumstances:
7. A trailer converter dolly that is not carrying a trailer. O. Reg. 199/07, s. 4 (1); O. Reg. 434/12, s. 1.

The act talks about trailer plates... but does not mention converter dolly plates .. it defines a trailer, and a trailer converter dolly
www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90h08_e.htm
“trailer” means a vehicle that is at any time drawn upon a highway by a motor vehicle, except an implement of husbandry, a mobile home, another motor vehicle or any device or apparatus not designed to transport persons or property, temporarily drawn, propelled or moved upon such highway, and except a side car attached to a motorcycle, and shall be considered a separate vehicle and not part of the motor vehicle by which it is drawn;

“trailer converter dolly” means a device consisting of one or more axles, a fifth wheel lower-half and a tow bar;

Permit for trailer
(4) No person shall draw a trailer on a highway unless,
(a) there exists a permit for the trailer; and
(b) there is displayed on the trailer, in the prescribed manner, a number plate showing the number of the permit issued for the trailer. R.S.O. 1990, c. H.8, s. 7 (4).

also.. this may apply if over 1360kg
www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90h08_e.htm

(2) No owner of,
(c) a trailer converter dolly,
shall draw or permit the trailer converter dolly to be drawn on a highway unless the trailer converter dolly, has a vehicle identification number permanently affixed. R.S.O. 1990, c. H.8, s. 10 (2); 2009, c. 5, s. 4.

I have a Home Made tow Dolly.....was towing it empty home one day last year and was stopped by one of waterloos finest...he said you have no plate on that dolly...I said they are not req'd and I had called MTO to clarify....he said I don't think so and made me wait while he made some calls......comes back to me and says your right and said free to go....and apologized but he learned something new....

In the future I will put a plate on it......why risk being stopped and detained...